The present invention relates to electrical machines.
It is known to use electrical machines, in particular three phase current generators for energy supply of a vehicle electrical system in motor vehicles. Claw pole generators are used for this purpose. They are very light and powerful and therefore are cost favorable. Embodiments with a single flow axial ventilation by an outwardly located fans are known.
In addition, so-called compact generators are used, which have two flow ventilations by means of two small inwardly located fans. The cooling air is aspirated axially and leaves the generator radially in the region of its stator winding head in a drive and collector ring shield. In order to guarantee an effective generator cooling in the case of high motor chamber temperatures, additional devices for fresh air aspiration are known.
The intensity of the cooling must be designed so that the temperature of the components of the generator do not exceed specific limits under all occurring border conditions. Conventional complete encapsulation against dust, dirt, and spraying water in utility vehicle generators increases the problems of the required heat withdrawal. Furthermore, closed generators are known with cooling ribs for surface cooling, as well close generator with liquid cooling, for example oil.